Table 1.

Characteristics of the studies

First author	Year	Race	Mean age	Gender	No. of participants	Quality score
Bazelier 1	2011	Caucasian	44.8	Mixed	38925	8
Moen	2011	Caucasian	37.1	Mixed	231	7
Bazelier 2	2012	Caucasian	43.6	Mixed	15056	7
Bazelier 3	2012	Caucasian	46.4	Mixed	68430	8
Bazelier 4	2012	Caucasian	36.9	Mixed	18399	8
Dennison	2012	Caucasian	NR	Female	52960	7
Ramagopalan	2012	Caucasian	NR	Mixed	7908570	9
Bhattacharya	2014	Caucasian	65	Mixed	1066404	9
Gregson	2014	Caucasian	≥ 55	Female	60393	7

NA, not reported.